Never have these two teams been quite so dominant. Barcelona's 39-match unbeaten run in 2015-16 was the finest in the history of the Catalan club, but less than a year on, Real Madrid have matched it.
After going down 2-1 at Sevilla in October 2015, Barca did not lose again until defeat to Madrid in the Clasico last April. And even though Real lost their next match, a 2-0 defeat away to Wolfsburg, they have not been beaten since.
Barca's run came in one season, while Madrid's streak has arrived across two campaigns. So which of the two teams has the edge?
In their 39 matches without defeat, Barca won 32 and drew seven. Madrid, meanwhile, have won 30 and drawn nine. The Blaugrana also scored more goals: 122 compared to 112 netted by Los Blancos. Luis Enrique's men conceded fewer, too (23) than Zidane's side (36).
There were 19 clean sheets for Barca in that time (compared to Madrid's 14). But the number of different scorers (22 for Real, 12 for the Catalans) highlights Los Blancos' strength in depth over the past few months.
Madrid's streak has also lasted longer (276 days to Barca's 182), but that is only because Zidane's side have put together their run either side of the summer break.
Lucas Vazquez (32) has appeared in more matches than any other Madrid player in his side's streak, while Ivan Rakitic (34) featured in the most games in Barca's successful spell. During the respective runs, Luis Suarez topscored for the Blaugrana with 37 (ahead of Lionel Messi with 31). For Real, Ronaldo leads the charts in that time with 26 strikes, followed by Karim Benzema with 14.
Only 45.5% per cent of Madrid's goals have come from their trio of Gareth Bale, Benzema and Cristiano, however, while Barca relied much more heavily upon Messi, Suarez and Neymar as the MSN trio provided 74.6% of their strikes in that time.
In terms of numbers, Barca's run is slightly superior. Luis Enrique's side scored more, conceded fewer and also won more games than Madrid. However, Zidane's side have the chance to set a new mark of 40 games unbeaten as they travel to Sevilla (with a 3-0 first-leg lead) in the Copa del Rey next Thursday, before facing Sevilla again (also away), Malaga and Real Sociedad (both at home) and Celta Vigo (away) in their upcoming Primera Division fixtures.
Both of these record runs are incredibly impressive, anyway, despite differences in numbers. And as both Luis Enrique and Zidane have been quick to point out, it is the titles that matter most for these two teams. Because without silverware, a successful streak will mean little at the end of the season.

The high point for Madrid is the fact that 22 players scored in the run, that is a real record that will last for decades.

Guy unbeaten na unbeaten, all the analysis just to put barcelona ahead. You are just worried that madrid will surpass the record deal with man, madrid is the better team.